1. Field of the Invention
The present invention relates to the identification of faults in medical ventilation systems and a corresponding raising of an alarm in case of faults.
2. Discussion of Background Information
During the ventilation, the medical ventilator and the respiratory system of the patient form a coupled-together pneumatic system. The medical ventilator and the respiratory system are pneumatically coupled by way of the patient interface system, which consists of at least the ventilation tube and the patient interface (e.g. endotracheal tube or mask).
The disconnection (interruption of the connection) in the patient interface system is an unwanted state in which there is partial or complete pneumatic decoupling of parts of the patient interface system, consisting of e.g. the medical ventilator, the ventilation tube and a ventilation mask. As a consequence of the disconnection, the patient is no longer ventilated or no longer ventilated to an adequate extent. It is therefore necessary for the medical practitioner to identify a disconnection. A detection of and raising of an alarm in relation to a disconnection are part of the prior art.
The detection can be carried out by way of a pressure or flow measurement. In the case of a pressure measurement only carried out in the vicinity of the ventilator or in the case of using additional components such as a filter or a connection tube (“catheter mount”) between exhale system and patient, this identification of a disconnection cannot be carried out by way of the pressure signal through the ventilator. When using the flow signal for detection, the detection threshold in the respiratory flow may be very different, depending on the connected components. In the case of a fixed detection threshold, there are false alarms or there is a lack of dependability.
However, it is not possible to set the alarm thresholds sensitively enough in the known ventilators, for example in order to trigger an alarm in good time where possible, as this would further increase the already unsatisfactorily high false alarm rate.
In view of the foregoing, it would be advantageous to have available an apparatus for monitoring a disconnection, which triggers an alarm in good time and reliably, while having a very low false alarm rate.